Installed Autothority chips today - wow!
05-05-2009, 10:33 PM
#77
Inventor
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Steve, you can have a copy of what's in my cars, to try. It's experimental, tuned to ~13.5 AFR overall in the base map, for use with the '87 FPR. While cruising, the O2 sensor pulls it up to 14.7. (LH2.2 is nice, in that it doesn't learn, so you can run whatever you want in the base map, unlike 2.3 which will adapt.) It's got some idle issues at certain temps, but otherwise seems to work well.
Last week I realized my WOT switch doesn't work on the new '85. I'm not going into WOT mode (which turns off the O2 loop), so I've been running at 14.7 all the time. I reprogrammed the analog output of it's LC-1 wideband to 13.5, so even at full throttle, the wideband is in control. This has made it really move out, combined with the mod chip.
Since the LC-1 has two programmable analog outputs, I'm thinking of permanently disconnecting the WOT input to the LH (either at the connector, or in code) and using a reed relay to switch the O2 sensor input to the LH from 14.7 at cruise, to 13.5 at full throttle, always closed loop.
Last week I realized my WOT switch doesn't work on the new '85. I'm not going into WOT mode (which turns off the O2 loop), so I've been running at 14.7 all the time. I reprogrammed the analog output of it's LC-1 wideband to 13.5, so even at full throttle, the wideband is in control. This has made it really move out, combined with the mod chip.
Since the LC-1 has two programmable analog outputs, I'm thinking of permanently disconnecting the WOT input to the LH (either at the connector, or in code) and using a reed relay to switch the O2 sensor input to the LH from 14.7 at cruise, to 13.5 at full throttle, always closed loop.
05-06-2009, 01:08 AM
#79
Captain Obvious
Super User
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Nothing can be gained, because nothing changed in the max HP department.
There are always some variances between dyno runs. I think those fall into the normal variance range.
Plus, there is a mention of the dipping AFR curves, being the higher hp curves having a 3 degree retard ignition possiblity , maybe due to a cooler dyno run. But, the bottomline, there was no difference in the fuel map of the new chips under WOT.
mk
There are always some variances between dyno runs. I think those fall into the normal variance range.
Plus, there is a mention of the dipping AFR curves, being the higher hp curves having a 3 degree retard ignition possiblity , maybe due to a cooler dyno run. But, the bottomline, there was no difference in the fuel map of the new chips under WOT.
mk
I dropped 2 tenths in the 1/4 mile with nothing more than a chip set. 2 tenths is a huge amount when you re running in the 13sec bracket. Both times the car was 100% stock, including the weight. Went from a 13.7 to a 13.5, that has to take at least 25hp to do it.
05-06-2009, 11:40 AM
#80
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Ken, I don't have an LC-1, and am not sure how to see if WOT switch is working. I do have an adjustable FPR, but don't know if it has enough range to make 55psi...also, if I use your chips, should I take out the EZF mod I got from you?
05-06-2009, 12:24 PM
#81
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the old style twin RRFPRs can get up to 55psi, but thats about it. on the S4s, I got the pressure up to 72psi with the RRFPR
mk
mk
05-06-2009, 02:44 PM
#82
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Steve, you don't need an LC-1, I was just rambling on about my next project.
You should check your WOT switch. It surprised me when I found mine wasn't working. You can do this at the diagnostic plug at the front of the engine. Check for ground at term. B at full throttle. (C is ground. A is oxygen sensor pulses.)
_C_
B_A
With the LH chip I'd give you, you can still use the wired EZF tweak. (You would have to remove the tweak if you use my EZF chip.) If you can't get 55psi out of your AFPR, I've found new '87 S4 FPRs on eBay for $40-60 by searching by the different part numbers below, or get a used one.
'87 FPR ('88-up is different)
3.8 bar/55 psi
928 110 198 02
Bosch - 0 280 160 262
Standard Motor Products - PR68
You should check your WOT switch. It surprised me when I found mine wasn't working. You can do this at the diagnostic plug at the front of the engine. Check for ground at term. B at full throttle. (C is ground. A is oxygen sensor pulses.)
_C_
B_A
With the LH chip I'd give you, you can still use the wired EZF tweak. (You would have to remove the tweak if you use my EZF chip.) If you can't get 55psi out of your AFPR, I've found new '87 S4 FPRs on eBay for $40-60 by searching by the different part numbers below, or get a used one.
'87 FPR ('88-up is different)
3.8 bar/55 psi
928 110 198 02
Bosch - 0 280 160 262
Standard Motor Products - PR68
